<?php
/*
 *  $Id: Mssql.php 7490 2010-03-29 19:53:27Z jwage $
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

/**
 *
 * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
 * @author      Lukas Smith <smith@pooteeweet.org> (PEAR MDB2 library)
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @package     Doctrine
 * @subpackage  Transaction
 * @link        www.doctrine-project.org
 * @since       1.0
 * @version     $Revision: 7490 $
 */
class Doctrine_Transaction_Mssql extends Doctrine_Transaction
{
	/**
	 * Set the transacton isolation level.
	 *
	 * @param   string  standard isolation level (SQL-92)
	 *      portable modes:
	 *                  READ UNCOMMITTED (allows dirty reads)
	 *                  READ COMMITTED (prevents dirty reads)
	 *                  REPEATABLE READ (prevents nonrepeatable reads)
	 *                  SERIALIZABLE (prevents phantom reads)
	 *      mssql specific modes:
	 *                  SNAPSHOT
	 *
	 * @link http://msdn2.microsoft.com/en-us/library/ms173763.aspx
	 * @throws PDOException                         if something fails at the PDO level
	 * @throws Doctrine_Transaction_Exception       if using unknown isolation level or unknown wait option
	 * @return void
	 */
	public function setIsolation($isolation, $options = array()) {
		switch ($isolation) {
			case 'READ UNCOMMITTED':
			case 'READ COMMITTED':
			case 'REPEATABLE READ':
			case 'SERIALIZABLE':
			case 'SNAPSHOT':
				break;
			default:
				throw new Doctrine_Transaction_Exception('isolation level is not supported: ' . $isolation);
		}

		$query = 'SET TRANSACTION ISOLATION LEVEL ' . $isolation;

		$this->conn->execute($query);
	}

	/**
	 * Performs the rollback.
	 */
	protected function _doRollback()
	{
		$this->conn->getDbh()->exec('ROLLBACK TRANSACTION');
	}

	/**
	 * Performs the commit.
	 */
	protected function _doCommit()
	{
		$this->conn->getDbh()->exec('COMMIT TRANSACTION');
	}

	/**
	 * Begins a database transaction.
	 */
	protected function _doBeginTransaction()
	{
		$this->conn->getDbh()->exec('BEGIN TRANSACTION');
	}
}